chore: add fade-in and fade-out

Author: segunadebayo

shared/src/css/keyframes.css

@@ -65,3 +65,21 @@
     transform: scaleX(1);
   }
 }
+
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+@keyframes fadeOut {
+  from {
+    opacity: 1;
+  }
+  to {
+    opacity: 0;
+  }
+}